I'm a problem using conference with calls between an internal 7931 IP Phone and two external GSM Phone.
To call gsm phones I use an IP GSM gateway (Quescom) with four simultaneous channels (4 GSM SIM)
Normally I haven't any problems when 1, 2, 3 or 4 users call external consumers using GSM gateway.
Now, if I try to start a conference: first call to outgoing user on GSM (for example: 03381234567), next press CONF on IPPhone display, next I try to digit
second GSM phone number, but on phone display appears "impossible to complete conference".
Note: for emergency calls on GSM numbers, (GSM gateway out of service or bad signal cell, etc), I have attivated to force outgoing calls on GSM numbers,
a numbers sequence to digit before to digit GSM number = 0 + 9 + GSM phone number. This mode enable user to call a GSM number using ISDN channels.
Using this method the conference between two external numbers and one internal works correctly, as between tree internal numbers too.
In attach the configuration on the router ISR 2821.
Please could you help me to solve this problem?
Thank you for best support
voice call send-alert
voice call convert-discpi-to-prog
voice call carrier capacity active
voice rtp send-recv
voice service pots
voice service voip
allow-connections h323 to h323
no supplementary-service h450.2
no supplementary-service h450.3
voice class codec 10
codec preference 10 g711ulaw
codec preference 13 g711alaw
codec preference 14 g729r8
voice class h323 1
h225 timeout tcp establish 3
load 7931 SCCP31.8-2-2SR1S
ip source-address 10.70.11.11 port 2000
timeouts interdigit 7
system message COMPANY
url directories http://10.70.10.30/fw/apps/speedy/xml/directory.asp
url authentication http://10.70.10.30/fw/authenticate.asp
max-conferences 8 gain -6
call-forward pattern .T
transfer-system full-consult dss
create cnf-files version-stamp 7960 Dec 13 2008 17:03:31
dial-peer voice 50 voip
corlist outgoing GSM CALL
description ** DIAL PEER CALL TO GSM GATEWAY **
translation-profile outgoing OUT-GSM-GW
voice-class codec 10
session target ipv4:10.70.11.12
dial-peer voice 70 pots
corlist outgoing CALL-CELLULARI
description *** OUTGOING FORCED CALLS CELLULARI TO ISDN***
progress_ind alert enable 8
progress_ind progress enable 8
progress_ind connect enable 8
translate-outgoing calling 1
dial-peer voice 71 pots
dial-peer voice 72 pots
dial-peer voice 73 pots
This could indicate a codec mismatch exists between IP phones used for conferencing.
Do one of the following:
Use the same codecs on phones used for conferencing, and make sure that all of the regions and conference bridges use the same codec. Use hardware conference bridges which can perform transcoding.